Calculating Power for a Coasting Car with Given Equation and Values | 1072 kg

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To calculate the power required for a 1072 kg car coasting at 18.05 m/s after 38 seconds, apply Newton's second law to determine the forces acting on the vehicle, including air resistance and rolling resistance. The speed function provided indicates that the car experiences deceleration due to these forces. Once the net force is calculated, use the power equation, P = F * v, where F is the total force and v is the constant speed, to find the necessary power output. This approach ensures that the car maintains its speed against resistive forces. Accurate calculations will yield the power needed to sustain the given velocity.
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A car with a mass of 1072 kg is coasting in neutral on a straight,level road. It slows down, and its speed as a function of time is given by the equation:
v(t) = a − bt + ct2



Constant Value Units
a 26.8 m/s
b 0.310 m/s2
c 2.10·10^-3 m/s2

At a time of 38.0 s the speed, as given by the above equation, is 18.05 m/s. Calculate the power which the engine must deliver (to compensate for air resistance and rolling resistance) in order to maintain that speed.

This is the problem; but I couldn't solve it. Please help.
 
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Have you made an attempt at a solution (per Forum rules)? Try using Newton's second law to find the force acting on the car after 38 seconds, then recognize that the car moves at constant velocity thereafter , and use the equation for power required to maintain that speed. Please list the relevant equations. And welcome to PF!:smile:
 
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